His challenge is aimed at raising awareness of environmental issues like climate change and food waste, and he's now working on a book all about his project, for which he's hoping to get crowd-funding to pay for the publication.

As well as climbing trees, the 36-year-old interviewed environmentalists, economists, politicians, philosophers and even children about the environment and how it can be protected.

Highlights of his trip include climbing a tree with 43 other people, speaking to a class of nine-year-old children and having a 'family tree party' in Norway, where some of his family is from.

Henrik said:

"I'm interested in environmental issues and social change. People are almost getting tired of hearing about climate change - the tree-climbing project is a fun way of engaging with environment and politics.

"There are so many little projects people can get involved with within our lives. We can't keep wasting food the way we do. It's actually harming people in other countries as well as causing climate change.

"I hope people get a sense of the urgency but also the wonder of nature."